Best Approche Cpp

string superReducedString(string s) { stackstack;

for(char ch : s){
    if(!stack.empty()){
        if(stack.top() != ch){
            stack.push(ch);
        }else{
            stack.pop();
        }
    }else{
        stack.push(ch);
    }
}

if(stack.empty()){
    return  "Empty String";
}

string ans = "";

while (!stack.empty()) {
    ans.push_back(stack.top());
    stack.pop();
}

reverse(ans.begin() , ans.end());

return  ans;

}